1. Field of the Invention
This invention relates to a novel hedgehog protein, more particularly, a Desert hedgehog protein of human origin.
2. Description of the Prior Art
The hedgehog gene was originally identified by genetic techniques as a gene that plays an important role in normal morphogenesis during embryonic and larval development in the fruit fly Drosophila melanogaster, as described by C. Nusslein-Volhard et al., in Nature, Vol.287, pp.795-801 (1980). J. J. Lee et al. sequenced the gene and deduced the amino acid sequence of the hedgehog protein as the expression product in Cell, Vol.71, pp.33-50 (1992). Some homologues of the gene were later isolated from vertebrates including mammals (hereinafter, the homologues of species other than the fruit fly may also be called “hedgehog”). At present, it is known that vertebrate hedgehog genes, unlike that of the fruit fly, form a multigene family and would play different roles in normal morphogenesis.
For example, as described by Y. Echelard et al., in Cell, Vol.75, pp.1417-1430 (1993), there have been identified three types of the genes of mouse origin, designated “Sonic hedgehog”, “Indian hedgehog”, and “Desert hedgehog”, which have different nucleotide sequences and express in different manners in living bodies. While in human, there have been found only two types of the genes designated “Sonic hedgehog” and “Indian hedgehog”, as described by V. Marigo et al., in GENOMICS, Vol.28, pp.44-51 (1995), and their expression manners and functions of their expression products remain to be elucidated. Therefore from scientific and pharmaceutical viewpoints, in order to elucidate the process of exhibiting hereditary morphological abnormalities in humans and direct research their treatments and diagnoses, the establishment of a novel hedgehog gene and its expression product, i.e. a novel hedgehog protein, is now in great expectation demand.